Known examples of medical connectors include a connector for connecting a patient side transfer tube (extension tube) with a peritoneal dialysis unit when a dialysis solution for peritoneal dialysis is exchanged. Peritoneal dialysis is a medical treatment method in which a dialysis solution is stored in a patient's abdominal cavity by way of a peritoneal catheter that is implanted surgically in the patient's abdominal cavity beforehand, so that impurities accumulated in the body are filtered using capillary vessels in the peritoneum. The patient undertakes daily activities while a transfer tube (extension tube), which is used continuously for a half year, is connected to the end of the catheter. Then, the patient himself/herself connects a bag containing a dialysis solution with a front end of the transfer tube four times per day to exchange the dialysis solution in the abdominal cavity.
The most serious problem to be addressed for carrying out the peritoneal dialysis is bacteria in the air or attached to the skin inadvertently entering into the abdominal cavity with the dialysis solution during the operation of exchanging the dialysis solution, which is required four times per day. If bacteria enter into the abdominal cavity, these bacteria cause inflammation of the peritoneum to develop peritonitis.
Thus, in the peritoneal dialysis, it is important, when the dialysis solution is exchanged, to reduce the bacterial contamination of a connector that connects a transfer tube and a peritoneal dialysis unit. Conventionally, products for connecting tubes by melting with a heated copper plate or for disinfecting a connecting portion with ultraviolet rays are available commercially for preventing the bacterial contamination. However, since these products necessarily require units dedicated to the products, a patient always has to carry the unit. Moreover, in the event of problems with the unit, serious problems might occur.
Meanwhile, as for connecting members that do not require the units and can prevent the bacterial contamination, various structures have been examined. Examples of those ideas are a structure using a septum, which is pushed open to realize the fitting for connection and a structure where fitting is realized by breaking a film covering a connecting portion (see, for example, U.S. Pat. No. 4,610,469 A and JP 6(1994)-312014 A).
However, all of those connectors known conventionally have problems that their mechanism is complicated, their size is large, and the required functions cannot be obtained sufficiently, and therefore none of them have been put into practical use. In particular, there is no connector that is constructed by paying sufficient attention to the structure for preventing the bacterial contamination when the connecting and detaching are repeated.
These problems are not peculiar to connectors that connect a tube for peritoneal dialysis but are common to connectors for use in places where the connection between channels for a solution, such as a usual infusion solution, is required.